LLDB  mainline
UtilityFunction.h
Go to the documentation of this file.
1 //===-- UtilityFunction.h ----------------------------------------*- C++
2 //-*-===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef LLDB_EXPRESSION_UTILITYFUNCTION_H
11 #define LLDB_EXPRESSION_UTILITYFUNCTION_H
12 
13 #include <memory>
14 #include <string>
15 
17 #include "lldb/lldb-forward.h"
18 #include "lldb/lldb-private.h"
19 
20 namespace lldb_private {
21 
22 /// \class UtilityFunction UtilityFunction.h
23 /// "lldb/Expression/UtilityFunction.h" Encapsulates a bit of source code that
24 /// provides a function that is callable
25 ///
26 /// LLDB uses expressions for various purposes, notably to call functions
27 /// and as a backend for the expr command. UtilityFunction encapsulates a
28 /// self-contained function meant to be used from other code. Utility
29 /// functions can perform error-checking for ClangUserExpressions,
30 class UtilityFunction : public Expression {
31  // LLVM RTTI support
32  static char ID;
33 
34 public:
35  bool isA(const void *ClassID) const override { return ClassID == &ID; }
36  static bool classof(const Expression *obj) { return obj->isA(&ID); }
37 
38  /// Constructor
39  ///
40  /// \param[in] text
41  /// The text of the function. Must be a full translation unit.
42  ///
43  /// \param[in] name
44  /// The name of the function, as used in the text.
45  UtilityFunction(ExecutionContextScope &exe_scope, const char *text,
46  const char *name);
47 
48  ~UtilityFunction() override;
49 
50  /// Install the utility function into a process
51  ///
52  /// \param[in] diagnostic_manager
53  /// A diagnostic manager to print parse errors and warnings to.
54  ///
55  /// \param[in] exe_ctx
56  /// The execution context to install the utility function to.
57  ///
58  /// \return
59  /// True on success (no errors); false otherwise.
60  virtual bool Install(DiagnosticManager &diagnostic_manager,
61  ExecutionContext &exe_ctx) = 0;
62 
63  /// Check whether the given address is inside the function
64  ///
65  /// Especially useful if the function dereferences nullptr to indicate a
66  /// failed assert.
67  ///
68  /// \param[in] address
69  /// The address to check.
70  ///
71  /// \return
72  /// True if the address falls within the function's bounds;
73  /// false if not (or the function is not JIT compiled)
74  bool ContainsAddress(lldb::addr_t address) {
75  // nothing is both >= LLDB_INVALID_ADDRESS and < LLDB_INVALID_ADDRESS, so
76  // this always returns false if the function is not JIT compiled yet
77  return (address >= m_jit_start_addr && address < m_jit_end_addr);
78  }
79 
80  /// Return the string that the parser should parse. Must be a full
81  /// translation unit.
82  const char *Text() override { return m_function_text.c_str(); }
83 
84  /// Return the function name that should be used for executing the
85  /// expression. Text() should contain the definition of this function.
86  const char *FunctionName() override { return m_function_name.c_str(); }
87 
88  /// Return the object that the parser should use when registering local
89  /// variables. May be nullptr if the Expression doesn't care.
90  ExpressionVariableList *LocalVariables() { return nullptr; }
91 
92  /// Return true if validation code should be inserted into the expression.
93  bool NeedsValidation() override { return false; }
94 
95  /// Return true if external variables in the expression should be resolved.
96  bool NeedsVariableResolution() override { return false; }
97 
98  // This makes the function caller function. Pass in the ThreadSP if you have
99  // one available, compilation can end up calling code (e.g. to look up
100  // indirect functions) and we don't want this to wander onto another thread.
101  FunctionCaller *MakeFunctionCaller(const CompilerType &return_type,
102  const ValueList &arg_value_list,
103  lldb::ThreadSP compilation_thread,
104  Status &error);
105 
106  // This one retrieves the function caller that is already made. If you
107  // haven't made it yet, this returns nullptr
109 
110 protected:
111  std::shared_ptr<IRExecutionUnit> m_execution_unit_sp;
112  lldb::ModuleWP m_jit_module_wp;
113  std::string m_function_text; ///< The text of the function. Must be a
114  ///well-formed translation unit.
115  std::string m_function_name; ///< The name of the function.
116  std::unique_ptr<FunctionCaller> m_caller_up;
117 };
118 
119 } // namespace lldb_private
120 
121 #endif // LLDB_EXPRESSION_UTILITYFUNCTION_H
lldb::addr_t m_jit_start_addr
An expression might have a process, but it doesn&#39;t need to (e.g.
Definition: Expression.h:96
bool ContainsAddress(lldb::addr_t address)
Check whether the given address is inside the function.
A class that represents a running process on the host machine.
bool NeedsValidation() override
Return true if validation code should be inserted into the expression.
std::string m_function_text
The text of the function.
FunctionCaller * GetFunctionCaller()
Encapsulates a single expression for use in lldb.
Definition: Expression.h:33
"lldb/Target/ExecutionContext.h" A class that contains an execution context.
ExpressionVariableList * LocalVariables()
Return the object that the parser should use when registering local variables.
virtual bool Install(DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx)=0
Install the utility function into a process.
std::shared_ptr< IRExecutionUnit > m_execution_unit_sp
UtilityFunction(ExecutionContextScope &exe_scope, const char *text, const char *name)
Constructor.
static llvm::raw_ostream & error(Stream &strm)
std::string m_function_name
The name of the function.
bool isA(const void *ClassID) const override
"lldb/Expression/ExpressionVariable.h" A list of variable references.
FunctionCaller * MakeFunctionCaller(const CompilerType &return_type, const ValueList &arg_value_list, lldb::ThreadSP compilation_thread, Status &error)
Encapsulates a function that can be called.
"lldb/Target/ExecutionContextScope.h" Inherit from this if your object can reconstruct its execution ...
const char * FunctionName() override
Return the function name that should be used for executing the expression.
lldb::addr_t m_jit_end_addr
The address of the JITted function within the JIT allocation.
Definition: Expression.h:99
uint64_t addr_t
Definition: lldb-types.h:83
const char * Text() override
Return the string that the parser should parse.
Represents a generic type in a programming language.
Definition: CompilerType.h:33
std::unique_ptr< FunctionCaller > m_caller_up
static bool classof(const Expression *obj)
"lldb/Expression/UtilityFunction.h" Encapsulates a bit of source code that provides a function that i...
virtual bool isA(const void *ClassID) const =0
bool NeedsVariableResolution() override
Return true if external variables in the expression should be resolved.
An error handling class.
Definition: Status.h:44